EVALUATING THE EFFECTIVENESS OF NEW RADIOLOGICAL INDEX FOR THE DIAGNOSIS OF THE PECTUS DEFORMITIES USING COMPUTED TOMOGRAPHY IMAGING

Abstract

BACKGROUND: Chest deformities have an incidence of 1:1000 live births and with the wide spectrum of congenital chest wall deformities seen, pectus deformities are by far the most common anterior chest wall deformities. Many international indices have been utilized for the evaluation of pectus deformities which aid in categorizing the chest as normal or deformed. With every index presenting its own limitations and drawbacks, precise radiological assessment parameters delineating the limits of normal and pathological have not yet been defined. The present study has attempted to bring forth a new radiological index for the overall quantitative assessment of pectus deformities, by the inclusion of manubriosternal joint (MSJT) angulation or position alongside international radiological indices. The influence of MSJT alteration on mediastinal/intra-thoracic space has been assessed by correlating with Sterno-vertebral distance and transverse diameter of the chest.

AIM: Therefore, this study was aimed at evaluating the effectiveness of a new radiological index for the diagnosis of pectus deformities using computed tomography imaging.

 MATERIAL AND METHOD: his Case-Control study has been conducted in the Department of Radiology.30 subjects with mild to moderate pectus deformities and 50 controls, with the age group of 1- 40 years were evaluated for the study. Non-contrast computed tomography images with sagittal, axial sections were utilized for the measurement of the manubriosternal joint (MSJT) angle, VertebraI index, Haller’s Index, sterno-vertebral distance (SV), and the transverse diameter of the chest (a). The purpose of the study was explained to patients. Informed written consent was taken prior to the actual participation of the patient in the study.  Data were tabulated and statistical analysis was performed using ANOVA and unpaired student’s t-test.

RESULTS: The Sterno-vertebral distance was increased in the pectus carinatum and reduced in pectus excavatum in comparison with controls, which were found statistically significant, whereas the transverse diameter of the chest showed higher distance in pectus excavatum and lower distance in the pectus carinatum when compared with controls. Therefore, the sterno-vertebral distance had a positive correlation with MSJT angulation, whereas the transverse diameter of the chest showed a weak negative correlation. A comparison of international radiological indices in controls and cases was documented. In pectus carinatum, the vertebral index showed a lower mean of 18% and Haller index with a ratio of 2.08, whereas in pectus excavatum the vertebral index had a higher mean of 24% and Haller index with a 3.2 ratio, which was significantly higher in comparison with controls.

CONCLUSION: Only a better knowledge of normal anatomical parameters enables a better understanding of both normal and abnormal. Therefore, it was necessary to estimate the normal range of MSJT angulation so as to identify the extent of changes in MSJT angulation in pectus deformities. Our study has been the first of its kind where in the MSJT is being taken into consideration for measuring the severity of chest wall deformation. The knowledge about MSJT angulation can be used as an objective method for the assessment of patients with pectus deformities.

KEYWORDS: Pectus deformities; Manubriosternal angulation; Radiological index; Chest wall, Posterior depression, Configuration index, Vertebral index